This invention relates to a seat frame construction, particularly one for use with an aircraft passenger seat. Aircraft passenger seats are constructed from modular components, the size, weight and construction of which are dictated by many considerations, including fuselage dimensions, aesthetic and safety considerations. Many of these requirements are imposed by law or regulation. The lower seat chassis is constructed of leg modules, while the upper seat is constructed of section assembly modules. In prior art seating systems the leg modules and section assembly modules are connected by mounting both to a series of parallel beams which extend laterally from one side of the seat or seat assembly to the other.
The location of the upper seat section modules is controlled by the aircraft fuselage lines, statutory aisle requirements and carrier preferences within these parameters. The location of the leg modules is governed by the positions of the floor tracks which extend along the length of the fuselage and to which the seats are secured by track fittings on the bottom of the leg modules. The position of the floor tracks is generally fixed and permanent.
The variable position of the seats and the fixed lateral location of the legs relative to the floor tracks thus has required the fabrication of numerous parts intended particularly for a given seat for a given location. Many of these parts are fabricated for a specific location by the placement of holes in the components to attach them together, rendering them unusable in other positions within the aircraft. Prior art designs thus produce waste and inefficiency.
Therefore, it is an object of the invention to provide a passenger seat frame assembly which includes a minimum number of modular elements.
It is another object of the invention to provide a passenger seat frame assembly which permits a single configuration of a lateral beam element of the seat to be used for seats having various configurations and spacings.
It is another object of the invention to provide a passenger seat frame assembly which eliminates or reduces the need to drill attachment holes in beam elements specific to particular seat configurations and spacings.
It is another object of the invention to provide a passenger seat frame assembly which permits the beam elements to be attached to the leg module and section assembly module solely by clamping.
These and other objects of the present invention are achieved in the preferred embodiments disclosed below by providing a passenger seat frame assembly, comprising a seat bottom chassis including a plurality of leg modules and section assembly modules. The leg modules are attached to fixed, spaced-apart attachment points on a supporting surface, such as the deck of an aircraft fuselage. A plurality of beam elements are carried by the leg modules and section assembly modules. A plurality of clamp joints are provided for being positioned on the plurality of leg modules and for receiving the plurality of beam elements in spaced-apart relation to each other for defining a ladder frame assembly having a specified width and seat spacing.
According to one preferred embodiment of the invention, the clamp joint comprises an elongate attachment element for being attached to an upper portion of the leg module.
According to another preferred embodiment of the invention, the clamp joint comprises a beam collar for extending upwardly above the leg module for receiving a beam element.
According to another preferred embodiment of the invention, the beam collar includes a split therein from one lateral side to another for enabling the beam collar to assume a relatively large diameter position for receiving the beam therethrough.
According to yet another preferred embodiment of the invention, the beam collar includes tightening means for closing the split with the beam positioned therein to reduce the diameter of the beam collar and thereby clamp the beam therein against axial and rotational movement.
According to yet another preferred embodiment of the invention, the beam collar includes a threaded bolt extending though a matingly threaded hole through the joint clamp from one side of the split to the other for increasing and decreasing the diameter of the beam collar as the bolt is turned to thus loosen or tighten the grip of the beam collar on the beam.
According to yet another preferred embodiment of the invention, the clamp joint comprises an elongate attachment element for being attached to an upper portion of the leg module, the attachment element having a tapered end portion with a hole therein for receiving a fastener therethrough for attaching the attachment element to the leg module, an enlarged intermediate portion having a pair of spaced-apart holes therein for receiving respective fasteners therethrough for attaching the attachment element to the leg module, and a beam collar formed on an end of the attachment end remote from the tapered end portion for extending above the leg module and receiving a beam therethrough.
According to yet another preferred embodiment of the invention, the attachment element includes a web element between the hole in the tapered end portion and the pair of holes in the intermediate portion, the web element having a weight-reducing void therein.
According to yet another preferred embodiment of the invention, a passenger seat is provided, comprising a seat frame assembly which includes a seat bottom chassis including a plurality of leg modules and section assembly modules. The leg modules are attached to fixed, spaced-apart attachment points on a supporting surface. A plurality of beam elements are provided for being carried by the leg modules. A plurality of clamp joints for being positioned on the plurality of leg modules and section assembly modules. The clamp joints clamp the plurality of leg modules in spaced-apart relation to each other on the beam elements for defining a ladder frame assembly without the need to penetrate the beam elements with holes for receiving fastener elements such as screws or bolts. A seat bottom pan and a seat back pan are carried by the frame assembly. A seat bottom cushion is carried by the seat bottom pan and a seat back cushion is carried by the seat back pan.
According to yet another preferred embodiment of the invention, the seat includes an upholstery seat bottom dress cover positioned on the seat bottom and an upholstery seat back dress cover positioned on the seat back.
According to yet another preferred embodiment of the invention, the seat includes a meal tray carried by an aft-facing side of the seat back pan and movable between a stowed position against the seat back pan and a lowered, horizontal use position.
An embodiment of the method of mounting a passenger seat to attachment points on a supporting surface according to the invention comprises the steps of providing a seat bottom chassis including a plurality of leg modules and section assembly modules, the leg modules for being attached to fixed, spaced-apart attachment points on a supporting surface. A plurality of clamp joints are provided for receiving the plurality of beam elements therethrough. A plurality of beam elements is provided for being carried by the leg modules and section assembly modules. First and second ones of the plurality of clamp joints are positioned on each of the leg modules, and first and second beam elements are positioned laterally through the respective first and second clamp joints to attach the leg modules together in spaced-apart relation to each other. A section assembly module is positioned on the beam elements adjacent each leg module.